Door lock



May 5 1953 J. H. ROETHEL 2,637,582

- DooR LOCK Filed June 24, 194s v s sheets-sheet 1 EE- @MM QW rra/mixMay 5, 1953 J. H. ROETHEL 2,637,582

nooR LocK Filed June 24, 1946 3 Sheets-Sheet 2 @www May 5, 1953 J. H.ROEfHEL 2,637,582

DOOR LOCK Filed June 24, 1946 3 Sheets-Sheet 5 Wa/rA/EX Patented May 5,1953 UNITED STATES PATENT (HTFICEv DOOR LOCK John H. Roethel, Detroit,Mich., assignor to Roethel Engineering Corporation,

Detroit,

Mich.; a corporation of Michigan Application June 24, 1946, Serial No.678,991

30 Claims.

This invention relates to latch mechanism for swinging doors andparticularly, although n-ot exclusively, to latch mechanism which isespecially adapted to be used in connection with the doors of Vehiclebodies, such as automobile bodies. An object of the invention is toprovide a door latch which combines in relatively simple and compactform such desirable features as quetness of operation when closing thedoor, simplicity and compactness in construction, operational.efficiency and economy in manufacture.

Anotherobject of the invention is to provide an improved door latchembodying a latch bolt extending longitudinally at the free edge of thedoor and shiftable bodily in a generally vertical or up and downdirection by a rotative motion both when closing and opening the door,means being provided for locking or holding the bolt preferably in aplurality of positions and additional means of an improved, relativelysimple and ei'hcient character being provided for releasing the boltlocking means selectively from the inside and outside of the door topermit the door to be opened. Another object of the invention is toprovide anrimproved door latch mechanism for a swingunit for movement bythe spring means from door latched position to door unlatched position,

said locking means having a latch unlocked position and a latch lockedposition, said latch 4mechanism being provided with means effective whensaid latch unitA is out of door latched position for holding the lockingmeans out of latched locked position in an intermediate position, and afurther means, effective when said locking means is in said intermediateposition for mov- `ing said locking means from said intermediateposition into said locked position upon move- :ment of said latch unitinto d-oor latched position.

In accordance with the embodiments of the invention, herein illustratedby example, there is provided a movable latch unit mounted 'on Vasupport for the latch mechanism. The latch unit is movable between adoor latched position and adoor unlatched position and is under the 2influence of a spring means urging the latch unit at all times towarddoor unlatched position. A pivotally movable detent is provided which isadapted releasably to maintain the latch unit in door latched position,the detent having a latch released position and a latch holdingposition. An outer manually operable lever is provided which is operableto release or move the detent from latch holding position. Preferablythe release lever is fixed to the detent and is pivotally mounted onsaid support -to swing about a common pivot axis therewith. A lockingmeans is also provided which is engageable with the release lever forblocking the same and thereby preventing movement of the detent torelease the latch unit for movement from door latched to door unlatchedposition. The locking means is selectively movable into and out ofrelease lever locking position by manually operable means. The latchmechanism is further provided with means for engaging and blocking thelocking means against movement into locked position when the latch unitis in door unlatched position, said blocking means being renderedineffective to block movement of the locking means upon movement oi thelatch unit from door unlatched to door latched position. An importantfeature of the present invention is a means, efiective when said lockingmeans is engaged and blocked by said blocking means, for automaticallymoving said locking means into locked position upon movement of saidlatch unit into door latched position.

Other .objects of this invention will appear in the iollowingdescription and appended claims, reference being had to the accompanyingdrawings orming a part of this speciiication wherein like referencecharacters designate corresponding parts in the several views.

Fig. 1 is a fragmentary side elevation of a portion of an automobilebody provided with a swinging front door upon which the latch devicemade in accordance with the present invention is installed.

Fig. 2 is an enlarged vertical section taken substantially through lines2 2 of Fig. 1 looking in the direction of the arrows.

Fig. 2A is a face View illustrating in detail the rotatable boltcarrying plate and locking detent or dog therefor.

Fig. 3 is a view in elevation of the latch device ltaken substantiallyfrom position 3 in Fig. 2

looking in the direction of the arrow.

Fig. 4 is a horizontal section taken substantally through lines 4--4 ofFig. 3 looking in the direction of the arrows.

Fig. 5 is a fragmentary horizontal section taken substantially throughlines 5-5 of Fig. 3 looking in the direction of the arrows.

Fig. 6 is a fragmentary horizontal section taken substantially throughlines 6-,6 of Fig. 3 looking in the direction of the arrows.

Fig. 'I is a fragmentary horizontal section taken substantially throughlines 1 1 of Fig. 3 looking in the direction of the arrows.

8 is a plan view taken substantially from position 8 of Fig. 3 lookingin the direction of the arrow.

Fig. 9 is a vertical section'taken substantially ,y

:lines |2-I2'of Fig. 9zlooking in the direction of the arrows.

Fig. 13 isa section.takensubstantially through .lines |3|.3.of Fig. 9looking in the direction of -the arrows.

Before explaining in detail the present inven- ,tionit is to beunderstood thattheinvention is not limited in itsapplication'to thedetails of A'c :onstruction and arrangement of parts illustrated inthetaccompanying drawings, since the invention ils capable of otherembodiments andof being 4practiced or carried yout in various ways. Alsoit is to be understood that the phraseology or terminology employedherein `is for the purpose of description and not of limitation.

In the drawings there is illustrated, .by Vway vof example, oneembodiment of the present invention as applied to a door and doorl,frame structure, such as that of anautomobile body.

As illustrated in Fig. 1, the automobile body,

designated generally at A, is provided with av front door B which ishinged at its front edge so as to swing against a door post orbodypillar `C in accordance with conventional practice. VVIl'iedoorcomprises an outer metal door panel 21| and an inner metal doorpanel-2|, see'Fig. 2. JThe panel 2| terminates in a transverse jamb edgeor portion 2.2 (Fig. 8) facing the fixed jamb `face or edge `23 l(Fig.V3) ofthe door -frame post or body pillar C.

.Secured by .meansof screws 24 to the-inner side ofthe .jamb portion22of.the.door is -a case plate 25 having a flange 2.6 engaging the-inner side of the inner door panel 2|. .Mounted onthe -case plate y25is a bolt carrying plate or member 21 which islrotatable .uponapivot.orstud .28 in the formrof a shoulder rivet secured to the case plate.Rigidly fastened to the-.plate member 2.1 at a point spaced from the.pivotal axis 23 v iV-,hereof 4is acylindrical latch bo1t29. This'boltis carried by the plate 2 1 eccentrically thereof .and projectsoutwardly in a longitudinal horizontal direction through anarcuateslot3|l in the case plate and also through a similar andregisteringarcuate slot inthe amb face ,22 o f the door. Theseslots areooveredandclosed bythe plate 21 whenthedoor is open. The bolt carry-Vinsulate,2,1is,ifnrned ,units periphery at :the

tionor step ofthe bolt.

Associated with the bolt carrying plate 21 is a detent arm o-r cloggingmember 33 extending in the plane of the plate 21 and located therebelow.This arm 33 is riveted at 34 at an intermediate -point to a laterallyembossed or offset portion 35a.

formed in theelowerend of a detent actuating lever-35,this lever beingpivoted at its lower end so .as 'toswing inwardly and outwardly about apivot stud or shoulder rivet 36 secured to the case plate .and tothaembossed portion 35a of the lever. The upper end of the detentactuating lever F35 is guided in its swinging movement by means of aheaded stud or pin 31 extending through a guide slot 38 in a laterallyembossed orolsetportion 357;of the lever. Thev embossed or oifsetportions 35a and 3.519 of the lever 235 enable these portions of thelever 'to be positioned againstor proximate to thecase plate 25 whilespacing the intermediate portion of the lever away from the case plateso as to provide clearance for the bolt carrying plate 21 and the mainspring controlling the -same.

It will be noted that the boltcarrying plate 21, as viewed in Fig. A2,is rotatable in Aa clockwise direction Iwhen the bolt moves fromunlatched position toits latching position shown invFig. z2. The detentactuating .lever 35 is pivoted .at .36 vbelow the boltcarrying plate 21,and the outer end of thedetent arm 33 is `provided with'adog or detentportion 33a engageable successively `with the abutments 3| and 32 whenthedoor is closed. The detent actuating leve-r 35 ispreferably formedfromsheet steel in a single stamping and is suitably flanged-alongcertain of the-edges thereof .to .alford the necessary strength andrigidity.

The bolt carrying plate 21 is constantly urged =toward bolt unlatchingposition .and the detent arm 33 is constantly urged toward the plate 21.by means 0f a common main spring 39. This .spring inthe presentinstance has a plurality of intermediate coils terminating at one end inYan outwardextension 33a anchored at itsupperend .to a tongue 40 struckout from themetal of the lever 35. The main springalso terminates at itsVopposite end in an .upward Vextension 39h vanchored at.4| to theplate2.1 .at .a point above the `pivot 1.28 thereof. The spring 39 isinstalled under predetermined load ortension so as to exert constantrotative efforton the vbolt carrying plate 21 andthe detent actuatinglever 35. It will be seen cthat by mounting and connecting the mainspring as shown the spring will resist inward movement,

-i...e. tothe left in Fig. 2, of the lever 35and will also resistrotative .motion of the bolt carrying .plate 21 in a clockwisedirection, i. e. toward bolt latching position. From this constructionlit will lbeseenthat a single spring vmeans may be utilized to controlthebolt carrying plate 211andthe .detent actuating lever 35, this springproviding .a direct connection :between these parts. VThe outer edge ofthe lever 35 is formed with a lateral 43 or by any othersuitable meanssuch as a push Abuttonoperable from the outside of therdoor.

`'n accordance with the present invention improved remote controlmechanism is provided for swinging the lever 35 and detent arm 33 intoposition to disengage the detent arm from either the safety step orabutment 3| or the final step or abutment 32. This remote controlmechanism includes manually operable means, such as a door handle orpush button device, located on the inside of the door at a point remotefrom the case plate. The remote control mechanism comprises a bell crankor two arm lever 44 pivoted at 45 through the medium of a shoulder rivetto the case plate flange 26, see Fig. 3. The bell crank 44 includes alongitudinally extending offset arm 44a notched at its outer end tooverlie a lateral ilange 33h formed at the terminal end of the detentarm 33, see Figs. 2, 3 and 4. The lever 44 also has a depending leverarm 44h connected by a stud 46 to the slotted end 41 of a remote controllink 48 which is pivoted at its opposite end at 48a to the lower end ofa swinging lever 49. The upper end of this lever is pivoted at 50 to amounting plate secured to the inner door panel 2|. The lever is securedat its pivot 50 to the shank of the inner door handle (not shown) and isprovided with an upward projection 49a engaged by a spring 52 effectiveto return the lever to its normal position after the inner door handlehas been released. By turning the inner door handle to rock the lever 49the link 48 will be shifted to the left in Fig. 3, thus rocking the bellcrank lever 44, depressing the lever arm 44a which by engagement withthe flanged end 33h of the detent arm 33 will force the detentdownwardly from its position shown in Fig. 2 until the dog portion 33athereof clears and is free of the abutment 3| or 32 on the bolt carryingplate 21. When this action occurs the spring 39 will rotate the plate 21in a counterclockwise direction thereby shifting the bolt 29 to thelower end of the slot 3U in the case plate. A similar action occurs whenthe plunger 42fis shifted inwardly to rock the lever 35. It will beapparent from this construction that actuation of either the plunger 42or remote control lever 44 to free the detent from the plate 21 will beaccomplished one independent of the other.

In accordance with the present invention additional means is providedfor locking the bolt carrying plate 21 when this plate as well as thelatch bolt 29 has been moved to the nal locking position with the detentor dog portion 33a in engagement with the abutment or final locking step32 shown in Fig. 2. This additional locking means comprises a bell crankor two arm locking lever 53 pivoted at 54 to the case plate flange 26 bymeans of a shoulder rivet, see Fig. 3. The locking lever has a dependingarm 53a stamped to form an intermediate embossed portion or blockingprojection 531) which, as shown in Figs. 2 and '7, is arranged in suchmanner as to be shifted into and out of blocking position with respectto an inner ilanged edge portion d of the detent actuating lever 35. Theinside locking lever 53 is also formed with a longi- .tudinallyextending arm 53c lying against the inner face of the case plate flange26 and pivotally connected at its terminal end to a vertically extendingrod or plunger 55. This rod projects through the garnish molding at thelower edge of the window opening and carries at its upper end a knob orbutton 56 (see Fig. 1) which is accessible at the inner side of thewindow glass of the door. It will be readily seen that -when the knob orbutton 56 is pulled vupwardly the rod or link 55 will swing'the lever"53 about its pivot 54 thereby shifting the blocking projection 53h tothe position shown in Fig. 3 and the full line position shown in Fig. 7out of blocking position with respect to the flange portion 35d ofthe'detent actuating lever 35. `When, however, the knob or button 56 ispushed down to shift the rod 55 downwardly from the position shown inFig. 3, the depending arm 53a of the lever will be swung forwardlythereby shifting the blocking projection 53h to the dotted line positionshown in Fig. 'l into blocking or abutting relation with respect to thelever 35. When this occurs the lever will be blocked against swingingmotion in a counter-clockwise direction as viewed in Fig. 2, and anyattempt to release the detent arm 33 from the bolt carrying plate 21 byshifting the plunger 42 through the medium of the outer door handle 43or swinging the remote control lever 44 through the medium of the innerdoor handle will be prevented. vIn other words, when the blockingprojection 53D is moved into blocking position with respect to thedetent actuating lever 35, the door cannot be opened by manipulatingeither the inner door handle or the outer door handle.

The inside locking lever 53 may also be actuated by means of a keycontrolled device from the outside of the door, such device beingordinarily incorporated in oneor both of the front door locks butusually omitted in connection with the rear door locks of the vehicles.As illustrated in Fig. 3 the lower end of the arm 53a of the lockinglever 53 is provided with avertical slot 51 within which is slidable apin 58 attached to the upper end of a crank arm 59 pivoted at its lowerend to the case plate, the lever being provided with a square opening orsocket to receive a key actuated shaft 60. The` shaft is connected tothe cylinder mechanism of any conventional lock having the usual keycontrol. By turning the key in the lock in the outside of the door thecrank arm 59 may be swung fromthe position shown in Fig. 3 in aclockwise direction thereby'swinging the arm 53a Aand shifting theblocking projection 53h to its blocking `position shown in dotted linesin Fig. 7. Reverse turning of the key will swing the lever arm 53a inthe opposite direction to the position shown in Fig. 3 and in full linesin Fig. '1, thereby moving the blocking projection 53h out of blockingposition with respect to the detent actuating lever 35.

The inside locking lever 53 is yieldingly controlled by means of asnap-over spring 6| comprising an intermediate coiled portion, one endof the spring being anchored at 6 a to the case plate and the other endanchored at SIb to the lever arm 53e. This spring will yieldingly holdthe lever 53 in either its blocking or unblocking position by vreason ofthe fact that the point SIb passes above and below dead center when thelever is shifted to unblocking and blockingpositions respectively.

It will be seen that the latch bolt 29 is movable between unlatching andlatching positions in an arcuate path as defined by the arcuate slot 30in the case plate. The bolt is actuated when the door is closed by meansof a striker device which is mounted on the jamb edge 23 (Fig. 3) of thebody pillar or xed upright member of the door frame. In the presentinstance the striker device comprises a stamped metal piece 62 flangedentirely around its edges to provide strength and rigidity. This Strikermember 642 is adapted to be secured to the jamb'edge of the pillar er.door Vbv screws f5.3. and .Ls formed withaminwardlyand-upwardlyextendingslot or snideway @which in thenresentinstanee has straight parallel sides 54a and Mb -formed by theensine AQi the edges Qi ,thestrker so .as t0 afszrd ample bearing.engagement with the bolt 2 9 as olearlyshown in Fig. 3. The Widthof.the gnidewav 6.4 "approximates `the diameter :of fthe boi-t 29 [andusually-slightly greater .in order to @rieure Ytree movement of the`bolt thItOugh the enideway regardless of variations dueto allow.-ahle-.tolerances irl-production in thepresent L embodiment yof J.theinvention I provide yieldable wedging means cooperable. withthefstriirer easing .6-2 .and also with .the 4bolt to hold the doorrigidly against vertical ivibratory mation ,during Qneratien of lthevehicle. seeFigs- 9 :to 5.3 inclusive. This Wedging means .in thepresent ,instance comprises a stampedhollowcas, ing 265 o f generallyrectangular shape yand Open at the bottom. The-top Wall .65a ofthecasing projects through a slot in the vcase plate 25 .and is'penedover at 65h so as to rigidly secure `the c asing. tothe case plate.Extending'upwardly within .the casing .5 5 andy slidable therein .is a.wedge block 66, the outer face thereof being notchedtoreceive-t:he1outer depending wall 65C 0f the (easing, :as `,shown inEis. 1 2. The inner Yerlial Wall of .thewedge xblock :is -formed with a.grooveorguide slot .l-lV extending from end to end andadapied .toreceive aguide ribt pressed ontiof .the metal .of the caseplate 25.Com-municating with the guide `slot .6,1 is a shorter slot 6 9 ,which isl0f a shape and depth to receive a compression spring 1.9,. one end ofthe spring bCtOmng against the .closed end o f the slot 9 and ithe:otherendoi `the spring engaging a wall of :the casing, as shown in Fig.1 3. 'rhisspring is lnioiuited under v.initial load and .constantlyprees .the .wedge .block .5 6 toward vthe pos'tion shownin Fis. 1.0..fr-he top wall of the easing G2 ,is .inclined as shown .at ft2-a andthe bottom of the bleek 651s correspondinely` inclined as shown ata.

During `closing movement .of the door, las vthe ,Wedge .block :6B.travels from the position Vshown in |`Eig. 1i successively -to thepositions shown i-n Figs. .10 and.9, it .will engage .the inclinedsurface ,Ghini the easing and. `diie to irictional contact, will Lbeforced Zback to some yextent against the aetionof thefspring 1.9.Durinq'vehicle operation and .as .a resiilt of vibrations incidentthereto the .wedge will be constantly urged upwardly along the `inclined.surface 62a by the .spring 1,0 and thisv .action .will result inmaintaining the 4holt 29 izmly in .engagement with .the .upper ,inclinedWall 64a of the bolt guideway EL. Thus, .due to the action 0f the wedge$5 .the portion of .the striker .62 lying ,between .the b olt 29 and.the Iwedge will at all times be rigidly clamped therebetween regardlessof the -nal position taken b y 4the bolt Within the guide slot. positionwill vary slightly duri-ng use of .the v e.- hisle due te the fact that.the .door eis usually .pissed :asa-inst :a 'marginal rubberweatherstrinp ingwhioh @impresses -to a variable .extent .durmessage.

.the nresentexnbediment the construction is Such as t@ permit the lever.5 3 te be moved i@ blocking pesition when the detent .3.3 is envsasedwith the iinal locking .step .32 :but not when engaged with the vsafety .step 3i or when the daer is tuilropen. The heit plate 2i isprovided vwith additionai abutment .75 ha vins the .same depth as the:abutment .or Step 13l and, hence,

shallnwer .than the .step .32. `When .the .door `is Qleil A.with thebolt at 4.the ilower and of .slot the datent portion .3.311 #willfengage the step 1 5. Since thsstep is shallower than .theistep .32 willhold the idetent iarm a sslight distance lower than :its position .inFig. 2 and 'correspondingly willfhold thellev-er.faslightidistance tothe .left of iitsjposition in Fig. ,2. YThis .displacement .of the lever.35 v.will .be sufficient .to .project Vthe edge of the abutmentange35d. into thelpath of .the blocking :DrQJ'ection .5317, Vas showninAdotted lines in Fig. 7. iA similar position'of the ange .35d is sahenwhen .the detent isengaged-in the :safety Stap. .Whenthus positioned itwill be seen .that thesahutnient .flange 35d will prevent .the block ingprofetica-from ibeing shifted past lthe edge of the flange to blockingposition.

T:he spring 6;! may -loe mounted eo as .to return the .louer -53 `tonormal position, .shown by the iulllnes :in Figs. 3 and 7 ,except whenthe .blocking projection moves into blocking position, .or may befmountedas shownin Fig. 7 so as to throw. the .lever into blockingposition when .the door iaswungfclosed after ,first pushing down-on theknob l5 3 in theopenposition of .thedoorn With the door in ,open:position the knob 5B .may be depressed .a .short distance thusdepressing the lever ,arm 53e land .moving .the blocking.projectionagainstthe edge-oithe-lange35d (the latter beinginitheidottedline positionoi Fig. 7 When this occurs the ipoint of connection .ii-Ib.of :spring El will ,pass .below dead center a sl-ghtdistance, thusenabling .the spring to hold the blocking projection against .the flange35d. lf the `door is ythan 4 slaniined or swung closed, movement of thedetept .into the .final .step .32 will back 4the iiange 35d outof thepath iof .the blocking ,projeca .tion 53o .to the ldull line position.of Fig. 7. At theA instant .this ,occurs the spring Gil will .force theprojection -53b to block-ing position shown in dotted :lines in Fig..Thus with l.the :foregoing spring arrangement .it ,is possible to close,thedoorfrom .the outside and automatically lock the door withoutrequiring iiihe yuse .of .the key.

The step 1.5 on .the ,bQltpIate has thepadditiona-l .advantage .0Iensuring that the bolt 2 9 will `at all times assume a predeterminedposition when the door is open. Any upward shifting of the bolt when thedoor is open will be resisted by the spring loaded detent which will atall times 'ge the bolt plate to full unlocked position lwith the de tentin full engagement with step 75. This action .assists in maintaining thebolt in proper position with respect to the open end ,0f the strikervslot 64.

T O `ensure rapid and positive engagement of the detent with the nallocking step when the .door is slammed I- prefer lto provide anadditional coil spring .16- to assist the main spring 39. The inner endof spring is anchored to a struck- `out tongue i1 on the case plate andthe outer end 16a engages 'the undersidefof the detent arm thus urgingit upwardly toward locking position.

I claim:

1. In a .door control mechanism a movable latch unit supported formovement between a .door latched position and a door .unlatchedposition, spring means for urging said latch unit .at all times tow-ardsaid door unlatched position, a moi/able detent adapted releasably tomaintain said latch unit in door latched position and having a latchreleased position and a latch holding position. locking :means forpreventing release of said lat/ah unit for movement 'by said latchedposition.

2. In a door control mechanism, a latch unit supported for movementbetween a door latched position and a door unlatched position, a movabledetent adapted releasably to maintain said latch unit in door latchedposition and having a latch released position and a latch holdingposition, means for actuating said detent to rellease said latch unitfrom door latched position,

locking means for preventing release of said latch unit from doorlatched position, manually operable means for selectively moving saidlockingmeans into and out of a locked position in which release of saidlatch unit from door latched position is prevented, means for engagingand blocking said locking means against movement into locked positionwhen said latch unit is in door unlatched position, said blocking meansbeing rendered ineffective upon movement of said latch unit from doorunlatched to door latched position, and means, eective when said lockingmeans is engaged and blocked by said lblocking means, for automaticallymoving said locking means into locked position upon movekment of saidlatch unit into door. latched position.

3. In a door control mechanism a movable latch unit, Ya movable detentoperatively associated with said latch unit, said latch unit having anoperative or door latched position and an `operated or door unlatchedposition and being movable therebetween in latching and unlatchingdirections, said detent having a latch holding position in which itmaintains said latch unit in said operative or door latched position andbeing movable therefrom to a latch released position permitting movementof said latch unit in unlatching direction, a movable locking memberhaving a latch unlocked position, and a latch locked posit-ion, and anintermediate position therebetween, blocking means eiective when saidlatch unit is out of door latched position for holding said lockingmember against movement from said intermediate position into said latchlocked position, and means for automatically moving said locking memberfrom said intermediate position into said latch locked position uponmovement of said latch unit into door latched position.

4. In a door control mechanism, a movable latch unit, a movable detentoperatively associated with said latch unit, said latch unit having anoperative or door latched position and an operated or door unlatchedposition and being movable therebetween in latching and unlatchingdirections, said detent having a latch holding position in which itmaintains said latch unit in said operative or door latched position andbeing movable therefrom to a latch released position permitting movementof said latch unit in unlatching direction, a movable locking memberhaving a latch unlocked position, a latch locked position, and anintermediate position therebetween, blocking means effective when saidlatch unit is lout of door latched position for holding said lockingmember against movement from said intermediate position into said latchlocked position, means for automatically moving said locking member fromsaid intermediate position into said latch locked position upon movementof said latch unit into door latched position, and manually operablemeans for positioning said locking member in either latch unlocked,latch locked, or intermediate position.

5. In a door control mechanism, la movable latch unit, a movable detentoperatively associated with said latch unit, said latch unit having anoperative or door latched position and an operated or vdoor unlatchedposition and being movable therebetween in latching and unlatchingdirections, said detent having a latch holding position in which itmaintains said latch unit in said operative or door latched position andbeing movable therefrom to a latch released position permitting movementof said latch unit in unlatching direction, a movable locking memberhaving -a latch unlocked position, and a latch locked position, and anintermediate position therebetween, blocking means efiective when saidlatch unit is out of door latched position for holding said lockingmember against movement from said intermediate position into said latchlocked position, and spring means operatively associated with saidlocking member and adapted to urge said locking member away from saidlatch locked position when said locking member is in said latch unlockedposition and to urge said locking member toward said latch lockedposition upon `said locking member reaching a point between said latchunlocked position and said intermediate position during movement fromlatch unlocked position toward latch locked position.

6. In a door control mechanism, a movable latch unit, a movable detentoperatively associated with saidlatch unit, said latch unit having anoperative or door latched position and an operated or door unlatchedposition and being movable therebetween in latching and unlatchingdirections, said detent having a latch holding position in which itmaintains said latch unit in said operative or door latched position andbeing movable therefrom to a latch released position permitting movementof said latch unit in unlatching direction, a movable locking memberhaving a latch unlocked position, and a latch locked position, and anintermediate position therebetween, blocking means effective when saidlatch unit is cutof door latched position for holding said lockingmember against movement from said intermediate position into said latchtion, and manually operable means for moving said locking member from,said latch unlocked position to said intermediate and latch lockedpositions and return.

7. In a 'door control `mechanism, a movable latch unit, a movable detentoperatively associated with said latch unit, said latch unit having anoperative or door latched position and an operated or door unlatchedposition and being .racontez locked position, and an intermediateposition therebetween, blocking means effectivewhen said latch unit isout of door latched position for holdingsaid locking memberagainstmovement fromr said intermediateposition into said latch lockedposition, spring means operatively associated with said locking memberand adapted to urge said locking member awayfromv said latch lockedposition when said locking member is in said' latch unlockedpositionandI to' urge said locking member-toward said latch locked: positionupon said' locking member reachingia point I between said latchunlocked: positionY and' said intermediate positionV during movementfrom latch` unlocked position toward. latch locked Vposition, andmeans', manuallyroperablexfromtheinnerA` side of the doorA with which;the; mechanism isfused, for moving'said locking member from said latchunlocked to Said intermediate and latch locked positions 'andv return;

8i In a doorl control mechanism; a movable latch` uniti, a movabledetent operatively associated with said latch-unit, said. latchk unithaving an operative-f or door latched positionland an operated'- or'door unlatchedI position and being movable therebetween in:` latchingiand unlatching` direction; said-f detent havingra latich holdingposition in` which it maintains,saidilatch unit in saidl operativeordoorlatchedposition and; being movable therefrom: to, a', latch.released position permitting'movementio said". latch unit inunlatchingk direction,- a movable locking mem-l berhaving a.I latch:unlocked'. position,- a latch locked position, and arrV intermediateposition therebetween, blocking meansleiectivewhen said`l latch unit isouty of. doorlatched position for holding said lockingimember againstmovement from' said* intermediate position` into said latchlockedposition',v andi means, including a snap-over spring, for: holding saidlocking member in said-` intermediate; position after beingmovedthereinto when'ysaid latch-unit islin' door unlatchedipositioni andfor automatically moving said`r locking member.u from saidr intermediateposition'into .saidslatclr lockedipositionwhen said latchunitfmovesfrom. door unlatchedinto: door latched position;

9'. In a door. control mechanism'y ai movable latch unit, a movablekdetent; operatively associated with. said=latchunit, saidlatchunithaving operative or. door latched position` and an operatedorf doorunlatched position.v and being movable therebetween in; latching andAunlatching directions,y said detent having a latch holding position inwhich litrnaintains. said latch unitin said'. operative or door latchedposition and being movableitherefrom to-a latch released positionpermitting movement of said latch unit in unlatching direction, amovable locking member. having a. latch unlocked position; a latchlocked position, and an intermediate position therebetween, blockingmeans'elective when said spring, for holding saidlocking member: in:said intermediate position after being moved thereinto When said latchunit is in door unlatched position and for automatically moving saidlocking member from said intermediate position into said latch lockedposition when said latch unit moves from door unlatched into doorlatched position, and manually operable means for positioning'saidlocking member in either latch unlocked, latch locked, or intermediateposition.

10..In a door control mechanism, a movable latch unit, a movable detentoperatively associated with said latch unit, said latch unit' having anoperative or door latched position and an operated or door unlatchedposition and-being movable therebetween in latching and unlatchingdirections, said detent having a latch holding position in which itmaintains said latch unit-in saidoperative or door latched position andbeing movable therefrom to a latch released position permitting movementof said latch unit in. unlatching direction, a locking member havingl a'latchv unlocked position, a latch locked position, and an intermediateposition therebetween, locking member blocking means arranged tobemoved-fromblocking to non-blockingposition. concurrently with movementof saidlatch unitfrom door unlatched to door latched position wherebysaid blocking means is effective to hold said locking` member againstmovement from.` said intermediatev position intoy said latchlockedlposition when said latch unit is out of door latched position,and spring means for urging said locking member fromv said intermediateposition, into said locked position whereby, when said latch unit is indoor unlatched position and said lockingmember is moved from saidunlocked position into said intermediate position, movement. ofSaidlatchA unit; into door latched position and concurrent. movement ofysaid blocking meansinto.=non-blocking position `will .permitlsaid springmeansitomove vsaid lockingI memberv from said intermediate,positionlinto said locked i posi- 'JOI'L lfl. In: a doorcontrol mechanism,- amovable latclrunit, a-movable detent: operatively associatedwith saidlatchunit, said latch unit having an operative or door'latched positionand an operated or door unlatched position andv being movablevtherebetween in` latching and unlatching directions, said ydetent havinga latch holding position in-.whi'chiitmaintains said latch unit in saidoperative or door latched position and'being movable therefrom to alatchreleased position permitting movement of saidl-atch unit inunlatching direction, v a, locking member having a latchunlockedposition, a latch locked position, landan intermediateposition-therebetween, locking: member blockingTV means `arranged to bemovedI from.`blocking to non-blocking position concurrently withmovement of said latch unit from-` door unlatchedv to door latchedposition whereby said blocking means is effective to hold said lockingvmember against movement from said-intermediate position into said latchlocking f position when said latch unit is out of doorlatched^positionspring. means for urging said locking means fromsaidintermediate position into.l said locked. position whereby, whensaid latch-unit is indoor unlatched position and said locking memberis-moved from said latch unlocked-into said intermediate position,movement Aof said'latch unit into door latched position and concurrentmovement ofY said bloking means into non-blocking position .will permitsaid spring means toizmovesad lockingrmember from said intermediateposition vinto fsaid'locked position,

and manuallyv operable means for positioning said locking member ineither unlocked, locked, or intermediate position.

12. In a door control mechanism, a movable latch unit, a movable detentoperatively associated with said latch unit, said latch unit having anoperative or door latched position and an operated 4or door unlatchedposition and being movable therebetween in latching Iand unlatchingdirections, said detent having a latch holding position in which itmaintains said latch unit in said operative or door latched positionIand being movable therefrom to a latch released position permittingmovement of said latch unit in unlatehing direction, a locking memberhaving a latch unlocked position, a latch locked position, 'and anintermediate position therebetween, blocking means for holding saidlocking member against movement from said intermediate position intosaid latch locking position when said latch unit is in its operated ordoor unlatched position, said blocking means being operativelylassociated with said detent for movement out of position to hold saidlocking 'member in its intermediate position concurrently with movementof said detent into latch holding position, and means for urging saidlocking -member away from said latch locked position when said lockingmember is in said latch unlocked position Iand toward said latch lockedpositionwhen in said intermediate position.

`13. In combination in a door ycontrol mechanism, a latch unit supportedfor movement beltween' a door latched position and a door unlatchedposition, a movable detent adapted releasablv to maintain said latchunit in -door vlatched position and having a latch released positionland alatch holding position, a, locking member supported for movementbetween a latch unlocked position and a latch locked position and havinglan intermediate position therebetween, lock member blocking meansassociated with said detent, said locking member having a portionpositioned to engage said lock member blocking means when said detent isin latchl released position whereby said locking member is held out oflatch locked position in :said intermediate position, and spring means'for urging said locking member away from said latch locked positionwhen in said latch unlocked position and toward said latch lockedposition when in said intermediate position-whereby said `lockingmember, after being moved from said `latch unlocked position tosaid'intermediate position, will be moved by said spring means into litslatch locked position upon movement of said detent into latch holdingposition.

14. In a door control mechanism, a frame structure, a latch unitsupported by said frame structure for movement between a door latchposition and a door unlatched position, a movable detent supported bylsaid frame structure and operatively associated With-said latch unit,said detent having a latch holding position and a latch releasedposition, a rlocking member pivotally supported on said frame structurefor movement between a latch unlocked position and a latch lookedposition, locking member lblocking means Veffective when -said latchunit )is out of door latched position to block said locking member outof latch locked position in an intermediate position, and spring meansei:- tending between said frame and said locking member, the commoncenter line between the pivotal support of said locking member and theeiiective point of engagement of said spring means with said framestructure passing between. the position of the effective point ofengagement of said spring means with said locking member when saidlocking member is in unlocked position and the position of sai-deffective point of engagement of said spring means with said lockingmember when said locking member is in said intermediate position,whereby when said locking member is in unlocked position said springmeans tends to maintain it therein and. when said locking member ismoved from unlockedy position toward locked position, said spring meanswill, after said effective point of engagement of said spring means withsaid locking member crosses said ycommon center line, urge said lockingmember toward its said intermediate and latch locked positions.

l5. In a door control mechanism, a fram structure, a latch unitsupported by said frame structure for movement between a door latchedposition and a door unlatched position, a movable detent supported bysaid frame structure and operatively associated with said latch unit,said detent having a latch holding position and a. latch releasedposition, a locking member pivotally supported on said frame structurefor movement between a latch unlocked an a latch locked position, saiddetent having a locking member blocking portion movable therewith, saidblocking portion being positioned to block said locking member out oflatch locked positionin an intermediate position when said detent is inlatch released position and to permit movement of said locking memberinto latch locked position when said detent is in latch holdingposition, and spring means extending between said frame and said lookingmember, the common center line between the pivotal support of saidlocking member and the effective point of engagement of said springmeans with said frame structure passing between the position of theeffective point of engagement lof said spring means with said lockingmember when said locking member is in unlocked position and the positionof said effective point of engagement of said spring means with saidlocking member when said locking member is in said intermediateposition, whereby when said locking member is in unlocked position saidspring means tends to maintain it therein and, when said locking memberis moved from unlocked position toward locked position, said springmeans will, after said effective point of engagement of said springmeans with said locking member crosses said common center line, urgesaid locking member toward its said intermediate and latch lockedpositions.

16. In a door control mechanism, a frame structure, a latch unitsupported by said frame structure for movement between a door latchedposition and a door unlatched position, a movable detent supported bysaid frame structure and operatively associated with said latch unit,said detent having latch holding position and a latch released position,a locking member supported on said frame structure for lineal movementbetween a latch unlocked position and a latch locked position, lockingmember blocking means effective when said latch unit is out of doorlatched position to block said locking member out of latch lockedposition in an intermediate position, an actuatingr lever for saidlocking member, said lever being pivotally mounted on l safidfram'e',meansifor operatively conn'ectingsaid lever- 'to said locliin'g member,V and I spring means extendingbetween said lever andsaid lil-ame, saidspring meanslbelng arrangedto urgeisaid lever inY adirection tomovesaid'llocking' member away from said intermediate!and'loclred'positions when saidlo'cking member is:inlunlockedposition and to urgesaid lever in a Adirection to move saidloclrfing'membertowardsaidint'ermediat'e land locked positions upon said locking memberreaching" a point between said unlocked' pos-itionand said.interrl'le'd-iateposition I during movement from unlocked" positiontoward'locled position.

1'7. Apparatus for locking adoor latch mecha'- nisrn; having;adoor'latched position and ai door unlatched position', against releasefrom door lat'ched position comprising, releasable means fornon-yieldingly'maintaining the latch mechanism in said latchedposition,a locking member supported for movement between a locked position and:an unlocked position, said looking member when in unlocked positionpermitting release of said door latch mechanism from' non-yieldingdoor-latched position and when in locked position preventing release ofsaid door latch mechanism from said door latched position, manuallyoperable means for selectively7 positioning said locking member ineither of said two positions, means for holding said locking member outof locked position when said latch mechanism is in door` unlatchedposition, vand means, effective when said lockingr member is held out oflocked position, for automatically movinr said l'ockiner memberintolocked position upon movement of said' latch mechanism into door latchedposition.

1S. In a-door control mechanism, a latch unit supported for movementbetween a doorlatched position, a secondary latched-position and a doorunlatched'positicn, means for releasably holdingr said latch `unit indoor latchedlposition,` means for' releasably holding'saidlatch unit insaid secondary latched position, locking means for preventing release ofsaidlatch unit from door latohed position, said locking means havingalatch unlocliedposition and a latch locked position, means effectivewhen said latch unit is in said'secondary 'latched position or in saiddoor unlatched position for holdingsaid locking means out of latchlocked positionl in an intermediate position, and means, effective whensaid lockinssmeans is in saidintermediate position, for movingsaidlo'sking' means from said intermediateposition intosaid'lock'edposition upon movement of'said latch unit into door latchedposition.

191 In a door control mechanism, a .latch unit supported for movementbetween a door latched position and a door unlatched position, apositive detent adapted releasably to hold said latch unit in doorlatched position. said detenthavinf: ar latch' holdin? position in whichsaid .latch unit is positively blocked against unlatching movement andalso a latch released position. means for'actuating said detent torelease said latch unit from door latched position, lockingr means :forpreventing release of said latch unit from door latched position, meansfor automatically moving said locking means into locked position uponmovement of said latch unit into door latched position, and manuallyoperable control means for selectively rendering said automatic meanseffective or ineffective to move said lookin? means into locked positionupon movement of said latch unit into door latched position.

' 2l); In a door control mechanism, a support, a movable latch unitcarried by said support for movementbetweenfa door latched. positionandra doorh unlatched position,1.spring; means: for urs.- ingvsaid'latchfunitat allftimesctoward said door unlatched position, apivotally movableV detent adapted releasably'tomaintain said'latchunitin door latched positionfa-nd'havinga latch released position and. alatch` holding positiom, am outer manually.' operable'rdetent-releaselever pivotally mounted on' said support and operable to f move said 1detent from said latch'holding; position to said' latch' releasedfposition,v locking.: means engageable with .said` release'lever forvblocking the same and 1 thereby preventing movementL of. said detent?to releasosaidv latch' unit', said'y locking means having; ailatchvunlocked: position and, a latch locked position, vmeans effective when"said latch unit is fout'of ldoorlatched position for' holding saidlockingmeans out of latch' locked posi'- tion in an intermediatevposition,y and means effective AwhenfY said" locking meansis. in asaidintermediate position formoving; saidlocking: means from z saict.intermediate position` into lsaid locked position upon movement/:ofisaid .latchrA unit. into dor'latched position.

21. In-.a door` control mechanism. afsupport, i a movable latch unit"carried by' said supporte for movement betweerna` door latchedzpositionandfa door:unlatchedfposition, springimeans forxurging saidlatch .unitat'fall times towardisaid doorfunlatchedv position,v a pivotallymovable" datent adapted'releasablytomaintain .said latch unit in doorlatched position'andhaving a" latch released position andralatchholding-position, an outer manuallyfoperable i detent' releaselever. pivotally mounted on said` support andi' operable s tor movesaid*y detent fromsaidlateh holding positionto saidlatchlreleels'ed.position; saidd'etent andisaidrelease'leverbeingpivotally mount'e'don saidsupportY to swin'g about' afcommon pivotal .axis;,lc|'ok' ing'me'an's for preventing'release'oftsaidilatch uniti for movement by said spring' means: fromdoor 'latched position: todoor 'onlatchedpositiom said' locking 'meanshaving ia: latch unlockedipositionV and a latchlockenfposition,.meanszeflectlve when said'llatoh unit visv` out' ofdoor'ilatched'zposttion for holding saldilocking"meansTout'oitl latchlocked position 1 irri an".z intermediate". position;l and meanseffectivek when. said locking means'lsin s'a'id'- intermediate`positionkfor moving'said :locking means' from said intermediatepositioninto said looked position .uponm'ovement of: saidrlateh Limitintol door. lat'chedpostion;

22.v In a1 door; control meelianism; a: suppoma movable' latch'` unit.'Icarried'; byv said supportiy for movement' between a" doorla'tchedrposition anda door: unlatched=` position; spring means'y fonurgingsaidrlaitoh` unitiatall timesA toward said: door unlatched position',a'. pivotally' movable detent adapted releasably to maintain'saidlatchun'it in door'latcliedpositlon and having ra' latch releasedposition and a' latch' holdin'g'p'osition, an outer manually 'operable fdeten't' release-f: lever plvot'ally mounted on said support andoperable to move said detentfrom-said' latch holding position-to said.latch released' position, lockingi'means engageable with saidi release.lever'fo'r blocking: the same and thereby preventing movement ofi saiddetentA to release saldi latch' unit, said. locking means having' alatch unlockedl position and a latch locked position1 means' onsaidrrelease lever effective when saidvv latch" unit is out of' doorlatched positionfor holding said locking means out of' latchlockedposition" in-an intermediate position, and means effective whensaid'lock'ing meanslisin said intermed'iateposition for' movpostionzintosaidiiockd positioniuponimovementloffsaiddatchr-Junit-into.fcloonlatchedposition:v

23:*- Iniadoorfcontrolimechanism, afsupport; ai' movable `i.1atol:i.':unit carried fby ffsaid :support l for movementhetweenlvaldoor.-latohed` positioni and 1aI doorunlatc'hedl position;`springmeans .for urgf ing-2 sai'dllatch .unitiatalll times toward saidv"door". unlatched position; .arlvpivota-llyrfmovablei detent.adaptedireleasablyto maintainfsaidu latch unitrini doorllatchedposition*andfhavingarlatch'releasedff position and iaflatchholdii'igposition, anffouter manuallyfoperable detent :releaseY lever .1pivotally mounted oni:` said support? and operable 1 oo-"mover: saiddetent-from'.saidilatchfholding .position ytofsaidav latch .released fposition3llocklngl meansvf engage# able rwithv said -release ylever 'forblock-ingfth'esamef andztherebypreventingzmovement ruf-"said detentfl to=re1ease1 saidtlatch unitzfsaidilocking meanshavr fing-'alrlatchf'unlocked posi-.tion and anlatchf locked? position, f.means-*effe ctifv'e i whenf said 'latch" unit4 is 1 outy` ofi' doorlatchedipositionV for.' holding-v said* locking fm'eans i outf vvofAila-tch" lockedpositionfin anti intermediateposition, and 'springmeansoeectiver when said locking-:means is? finfsa-id. intermediate.:

position for moving said locking means from saidntermediate:=positiorrinto said locked position upon movement of saidlatch unit into door latchedrposition 24. In a:doorffcontrol.mech'anismasupport a movable..latch unit carried bysaidsupport, fore movement between a door latched positioniand adoorunlatched position, springmeans forHur-ging said 'latch unit at'all' times towardsaid door unlatched position', aV pivt'ntally.` movabledetent adaptedreleasably't maintai'risaid latchlunit in door :latchedposition Yand vhavingalatchireleased position" and "a" latch*h'oldi`rigposition, aniouter manually; operable detent releaseV` lever pivotallymounted *on;.said"`support` and "operable to move said *detentfrommsaidlatch holding positionto saidlatchreleased position; saiddetent andfsaidrel'e'aselever being pivotally mounted on said .sup-` porttoswin'g'about a common pivotal axis, locking means for preventingrelase'ofsaid latch unit for movement by said spring-1, means from.:ydoorr latched-.position to door unlatched.=.position, .saidlockingemeans having'a Alatchunlocked .position anda latch lockedposition, means onsaid release lever eiective when said latch unit isout of door z latched position for holding said locking vmeans out oflatch locked position in an intermediate position, and spring meanseffective when said locking means is in said intermediate position formoving said locking means from said intermediate position into saidlocked position upon movement of said latch unit into door latchedposition.

25. In a door control mechanism, a latch unit supported for movementbetween a door latched position and a door unlatched position, a movabledetent adapted releasably to maintain said latch unit in door latchedposition and having a latch released position and a latch holdingposition, means for actuating said detent to release said latch unitfrom door latched position, said last mentioned means and said detentbeing swingable about a common pivot axis, locking means for preventingrelease of said latch unit from door latched position, manually operablemeans for selectively moving said locking means into and out of a lockedposition in which release of said latch unit from door lat-ched positionis prevented, means for engaging and blocking said locking means againstmovement into locked position when said latch unit is in door unlatchedposition,

unit. inf. door :latchediposition4 andi having' a'latchre'leasedrposition.andzra latch holding position;

meanseforf 'actuating said` `detent `to release fsaid` latch .unit fromfdoor latchedtposition said'flast mentionedi meansrincluding amember'iswingable.l with sai'ddete'nt about ai'commonpivot axis;locl:-`

ing: .means or.` preventing release of said 'latch-.1

unitffr'om. door latched .position, manuallyopereable: 'means :forselectively Nvmoving".I saidlocking: means intoandfout of fa flockedpositionfiniiwhicli:A release' of. said'latchunit from door.latchedfposi'.- i tionis prevented, meansifor engagingand blocks:- ing`said. 'lockin'g means :against movement; into'; locked position'whensaidrlatch-z unitis in door.. unlatched" position;y said blocking."means fbeing'r renderedineifecti've upon movement of lsaid latch 1 unitfromdoortunlatched toidoor latched-position,

i andfmeans; eiectiveiwhen saidlockingfmeans. is f engaged andblockedibysaid. blocking fmeans, for

automatically'fmovingii saidi locking."y means into: locked'positicnuponmovementof said latch unit: into doorlatched position;

27.* Inadoor'control y`mechanism',. a latch :unit supported formovem'entbetween Aafdoor. rlatchedl, position and ia door unlatched 'position,..a.positive` .v detentfadapted Vrelea-sably to. hold.isaid.latch"funit in?door Ilatched;position;A said. detent' having as.) latch holding"position in: .which Lsaidxlatch. unit:vr

ist' positively blockedtagainst.v unlatching ymovement and alsoa'flatch1releasediposition; meansiforV actuating `said detent torelease. said. latch. unit" from. doorlatc'hed .r;position,..said 'lastmentioned 1 means including af... member;A attached i. to i said .L

detent for movement .therewithabout .arcommon'x pivot axis,`lockingrmeansfor preventing-release of'.4

said/.latchunitf :fromdoonxlatchedipositiong. means zr for;'automaticallymovingfsaidf locking meansdntor;

locked position upon movement of said latch unit into door latchedposition, and manually operable control means for selectively renderingsaid automatic means effective or ineffective to move said locking meansinto locked position upon movement of said latch unit into door latchedposition.

28. In a door control mechanism, a support, a movable latch unit carriedby said support for movement between a door latched position and a doorunlatched position, a lever means mounted on a pivot stud aixed to saidsupport and including a detent portion adapted releasably to maintainsaid latch unit in door latched position and having a latch releasedposition and a latch holding position, said lever means having a rstpart adapted to be engaged by outer manually operable means and a secondpart adapted to be engaged by inner manually operable means, both ofsaid manually operable means being operable to move said detent portionfrom said latch holding position to said latch released position,locking means engageable with said lever means for blocking the same andthereby preventing movement of said detent portion to release said latchunit, said locking means having a latch unlocked Aposition and a latchlocked position, means effec- 19 tive when said latch unit is out ofdoor latched position for holding said locking means out of latch lockedposition in an intermediate position, and means effective when saidlocking means is in said intermediate position for moving said lockingmeans from said intermediate position into said locked position uponmovement of said latch unit into door latched position.

29. In a door control mechanism, a support, a pivotally movable latchunit carried by said support for movement between a door latchedposition and a door unlatched position, said latch unit including aplate member having spaced safety and final locking steps. said safetylocking step having less effective depth than the nal locking step, alever swingably mounted on said support and having a detent -portionrigid therewith, said detent portion being releasably engageable witheither of said locking steps to hold said latch unit in door latchedposition, said lever having at its outer edge a lateral flangeengageable by an outer manually shiftable plunger adapted to swing saidlever to move said detent portion from a latch holding position to alatch released position, said lever having a latch released position, anintermediate position when said detent portion is in engagement withsaid safety locking step, and a nal latch locked position when saiddetent yportion is in engagement with said nal locking step, lockingmeans having a latch locked position and a latch unlocked position andengageable with said lever when the latter is in final latch lockedposition for blocking the same to thereby prevent movement of saiddetent portion out of holding position relative to said nal lockingstep, said lever when in said latch released position or saidintermediate position having a portion thereof blocking movement of saidlocking means from its latch unlocked position to its latch lockedposition.

30. In a door control mechanism, a support, a pivotally movable latchunit carried by said support for movement between a door latchedposition and a door unlatched position, said latch unit including aplate member having spaced safety and final locking steps, said safetylocking step having less effective depth than the nal locking step, alever swingably mounted on said support and having a detent portionrigid therewith and also a blocking portion, said detent step, a lockinglever pivotally mounted on said support and having a latch lockedposition and av latch unlocked position and also having a portionengageable with said blocking portion when said lever is in nal latchlocked position for blockingV the same to thereby prevent movement ofsaidy detent portion out of holding position relative to said iinallocking step, said lever when in said latch released position or saidintermediate posi-4 tion having a portion thereof booking movementv ofsaid locking means from its latch unlocked position to its latch lockedposition.

JOHN H. ROETHEL.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 506,665 Brown et al Oct. 17, 1893 1,544 960 Watts July 7, 19251,743,637 Taylor Jan. 14, 1930 1,937,520 Lightner Dec. 5, 1933 2,017 244Gudmundsen Oct. 15, 1935 2,094,413 Schonitzer Sept. 28, 1937 2,146,379Rediger Feb. 7, 1939 2,156,874 Schonitzer May 2, 1939 2 231 075 LakinFeb. 11, 1941 2,301,221 Mar-ple NOV. 10, 1942 2,394,646 Wagner Feb. 12,1946 2,480,688 Allen Aug. 30, 1949 FOREIGN PATENTS Number Country Date24,569 Norway Mar. 4, 1913 25,596 Great Britain May 13, 1907

